고위험 임산부에 있어서 임신 제 1 삼분기 중 염색체 이상 진단을 위한 Nuchal Translucency 의 유용성

이지영(Ji Young Lee),최규하(Kyu Ha Choi),박찬우(Chan Woo Park),윤태숙(Tae Suk Yun),박주진(Choo Jin Park),장봉림(Pong Rheem Jang),박양서(Yang Suh Park) 대한산부인과학회 1998 Obstetrics & Gynecology Science Vol.41 No.11

N/A Objective: To determine the value of sonographic nuchal translucency measurement for the detection of chromosomal abnormalities in high risk pregnancies. Method: The feasibility of nuchal translucency was tested in a prospective study of 1260 pregnancies at 10- 13 weeks' gestation. Results: The nuchal translucency of 3 mm or greater was identified in 41 fetuses (3.2%), 19 of whom proved subsequently by either amniocentesis or postnatal follow-up have chromosomal abnormalities. The sensitivity of nuchal translucency for chromosomal abnormalities was 82.6% (19 of 23 cases), the positive predictive value of nuchal translucency for chromosomal abnormalities detection was 46.3% (19 of 41 cases). Conclusion: The observed sensitivity, false-positive rate and predictive value suggest that sonographic nuchal translucency should be undertaken at 10 to 13 weeks of gestation.

형식개념분석(FCA)을 활용한 대학학업성취도 분석

조동헌(Dong-Heon Cho),최규하(Kyu-Ha Choi),황석형(Suk-Hyung Hwang) 한국컴퓨터정보학회 2016 韓國컴퓨터情報學會論文誌 Vol.21 No.4

This study had a purpose to find the correlation between academic achievement and entrance examination score using FCA and framing a concept of university academic achievement and entrance examination score and then, building concept lattice. The subject for this analysis was admission materials of freshmen in computer engineering department at A university located in Chungcheong area in 2010. Also 56 students in total were subjects for the score analysis of their first semester from 2010 to 2014. The major findings of this study were as follows. We organized and extracted many-valued context, concept lattice, associated rules using FCA. And we analyzed the correlation between University academic achievement and entrance examination score using FCA. The conclusions were as follows. We could get meaningful analyzed results using FCA. University academic achievement had lower relativeness with entrance examination score and female students had higher university academic achievement than male students. The improvement points are summarized below. It is necessary to improve the ratio and application method of the university admission factors and to increase the regular admission for a university. And programs for completing College-preparatory programming for male students in low university academic achievement are necessary.

복막에 발생한 원발성 유두양 장액성 악성종양

권민연(Min Yeon Kwon),이존익(John Ik Lee),우소영(So Young Woo),최규하(Kyu Ha Choi),박주진(Choo Jin Park),김덕환(Duck Hwan Kim),문종수(Zong Soo Moon),서수형(Soo Hyung Seo),박양서(Yang Suh Park) 대한산부인과학회 1999 Obstetrics & Gynecology Science Vol.42 No.8

Primary papillary serous carcinoma of the peritoneum(PPSCP) is vere rare. It has been suggested that PPSCP derives from embryonal coelomic epithelium with m llerian ducts potential. PPSCP can develop from a single or multicentric focus. The clinical and histologic disease entities are similar to those of primary papillary serous carcinoma of the ovary, but PPSCP involves the ovarian surface only minimally(microscopic disease) or spares the ovaries entirely. We have experienced a case of primary papillary serous carcinoma of the peritoneum and report this case with brief review of the concerned literature.

鑄鐵熔接에 對한 一硏究 : on the practice of Cast Iron Repair Welding 鑄鐵補修熔接의 實際에 對하여

河載晧,崔圭夏 忠州大學校 1968 한국교통대학교 논문집 Vol.2 No.-

On the practice of Cast Iron Repair Welding in many cases, castiron like steel, the field of the use of castiron will be increadid. But castiron is difficatly welded because of many condition. As welding technic has been developing, the welding of cast iron is becoming the ofbect of study. The welding of cast iron requires such high technic that it is omitted especially in practice training for student, this point the purpose of this study lies in this point.

E.D.M의 가공특성과 가공변질층에 관한 연구

崔圭夏,朴達根 忠州大學校 1999 한국교통대학교 논문집 Vol.34 No.1

In this paper the study of wire-cut Electric Discharge Machining on high speed steel, the characteristics such as cutting speed and evaluated for discharge voltage, discharge current, water speed. Cutting speed are improved as discharge current, cutting speed and discharge low voltage show a few increased, many increased discharge high voltage. Cutting speeds are many increased water low speeds, a few increased water high speed. Damaged layer a few decreased discharge high voltage, Damaged layer a few decreased high discharge current. Damaged layer are little by little decreased high water speed, many increased low water speed.

信賴性있는 나사의 强度計算에 關한 硏究

崔圭夏 忠州大學校 1997 한국교통대학교 논문집 Vol.32 No.1

In order to become proficient, all machineng in automoil industry, flying machine industry, nuclear reactor, industrial machine and machine tools has generally used thread to contact bolts and nuts. So we have studied an important subject of thread strength, reliability and safety for contacting materials. In this paper, by way of using example, 1 have studied on the neliability and quality of thread and the contacting materials, and their stnength, design order and contacting method.

動力전달용 평치차의 Pitting에 對하여

鄭求海,崔圭夏 忠州大學校 1972 한국교통대학교 논문집 Vol.5 No.-

The author has reported already that the Lubricating conditions of the gears remarkably affect the endurance Limit of the pitting. To explain these phenomena theoretically, the author has analysed the hydrodynamic lubrication film of the gears, taking into account the elastic deformations of the rolling surfaces and the film temperature. In the present report, however, it is shown that the experimental results for the pitting are reasonablly explained with the aid of the above theoretical analysis. That is the thicker the theoretical film thickness is, the more the cut-marks of grinding of the gear surfaces remain after the running. Further, if the maximum film Pressure calculated on the basis of the above theory is taken instead of Hertz stress, the wohler curve becomes only one curve under various lubricating conditions. These results show that the pitting must be analyzed with the aid of the hydrodynamic film lubrication theory.

螺絲의 풀림 防止對策에 關한 硏究

崔圭夏 忠州大學校 1998 한국교통대학교 논문집 Vol.33 No.1

We have demanded the preventive the accident because fracture happened that thread with friction, vibration impact, sliding so on got loose by unexpected several forms. The cause of thread getting loose has happened to deflection by roughness from contact part, plastic deformantion insurface of seat, friction from contact part, deflection of gasket so on thread on the surface of seat, vibration from contact forcing vanishment and getting loose by wear. In this paper, I have studied the preventive of getting loose and effect on the thread which I had comparatively studied with result of experiment, for example, in case of vibration and impact without of getting loose rotation and with rotation.

두꺼운 回轉圓筒의 塑性變形에 關한 硏究

崔圭夏 忠州大學校 1985 한국교통대학교 논문집 Vol.18 No.2

A rotation cylinder as a kind of machine element has been used for centrifugal separator. However, there are few studies on that field. In this paper, I studied on the plastic deformation on the ground of the Aluminum rotating cylinder with various axial length and the occurrence of bulge, and the results from the study of stress condition of the elastic region and centrifugal fracture are as follows: 1. The bulge of rotating cylinder deformation and the end area concave of cylinder end parts are affected by axial length. 2. The bulge has a single type on the occasion of a short axial length, and has a double type on the occasion of a long axial length. 3. The condition centrifugal fracture should be decided on overage stress theory of the rotating disc regardless inside and outside diameter, and axial length. 4. The occurrence of shrink to a uxial direction has a maximum at the internal circumference, and has a minimum at the external circumference.

Dove-tail Notch의 幅變化에 따른 應力集中에 關한 光彈性學的 硏究

崔圭夏 忠州大學校 1991 한국교통대학교 논문집 Vol.25 No.-

When a load is put on the parts of the rapidly changing section area like in notch. fillet, keyway, screwthread etc., there may occur some stress concentration, crack and fracture in the structures of machines, buildings, bridges, ships, aircrafts, industrial plant machines, atomic power plant machines and the machines for civil engineering architecture or agriculture. Many researchers such as Neuber, Frocht, Vicentini, Flynn etc. have tried to find out the cause of fracture by photoelastic experiments. When Tuner settled the aircraft strcuture analysis by finite element method in 1956, Agyris, Ritz, C.A.Felippa, electric field, thermal transmission, underground water, soil, atomic technology, the ground, biotechnics, and even to the stress concentration problem which is one of the machine design field. There are some structural analysis methods of the strength of materials, photoelastic and the finite element method. They have the same object for design of strength and stiffness, but each method and priciple is very different. In this paper I studied the stress concentration and the stress distribution on Dove-tail notch by photoelastic and tried to show the relaxation of stress concentration.